661: Organic Light Emitting Diodes (OLEDs) are used to create digital display in many devices.

What are the advantages of OLED displays over Liquid Crystal displays?

1. OLED displays can be fabricated on flexible plastic substrates.
2. Roll-up displays embedded in clothing can be made using OLEDs.
3. Transparent displays are possible using OLEDs.

Select the correct answer using the code given below

(a) 1 and 3 only
(b) 2 only
(c) 1, 2 and 3
(d) None of the above statements is correct
662: They are fantastically diverse. They speak hundreds of languages and dialects. They comprise scores of ethnic groups. They include highly industrialised economies and up-and-coming economies. They span half the surface of the earth and are home to two-fifths of the world's population. The group of countries referred to here belongs to

(a) SAPTA
(b) APEC
(c) EC
(d) CIS
663: Two important rivers - one with its source in Jharkhand (and known by a different name in Odisha), and another with its source in Odisha - merge at a place only a short distance from the coast of Bay of Bengal before flowing into the sea. This is an important site of wildlife and biodiversity and a protected area.

Which one of the following could be this?

(a) Chandipur-on-sea
(b) Gopalpur-on-sea
(c) Bhitarkanika
(d) Simlipal
664: Which one of the following was initially the most powerful city state of India in the 6th century B.C. ?

(a) Gandhar

(b) Kamboj

(c) Kashi

(d) Magadh
665: Assertion (A) :

The southern half of India lies within the tropics and the northern half belongs to the warm temperate zone

Reason (R) :

The tropic of cancer runs almost halfway through India

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not a correct explanation of A

(c) A is true but R is false

(d) A is false but R is true